[statespace] less restrictive test for regular statespace model
[statespace] less restrictive test for regular statespace model

esiivola/GPYgradients,mikecroucher/GPy,dhhjx880713/GPy,mikecroucher/GPy,ysekky/GPy,SheffieldML/GPy,befelix/GPy,avehtari/GPy,mikecroucher/GPy,esiivola/GPYgradients,ysekky/GPy,avehtari/GPy,SheffieldML/GPy,esiivola/GPYgradients,dhhjx880713/GPy,avehtari/GPy,dhhjx880713/GPy,mikecroucher/GPy,ysekky/GPy,befelix/GPy,befelix/GPy,avehtari/GPy,befelix/GPy,dhhjx880713/GPy,esiivola/GPYgradients,SheffieldML/GPy,SheffieldML/GPy,ysekky/GPy